jal15

=__Galileo Galilei__=

By jal15
Galileo Galilei was born on February 15, 1564 in Pisa, Italy, and is one of the most famous scientists. He is a well-known Italian physicist, mathematician, and astronomer throughout the world. He is most commonly known for his discoveries of Jupiter’s four largest moons, the phases of Venus and the Moon, the sunspots, and the law of falling bodies. His overall fame came from his trial in Rome about disagreeing with the church by saying that the Earth is not at the center of the solar system, but the Sun is. All the observations that he has made throughout his lifetime has influenced and contributed to the science that we now learn and use.

__ Jupiter’s Moons __
Galileo’s discovery of Jupiter’s four largest moons was just the beginning for him. He first concluded that there were moons on March 22, 1610. Galileo first thought they were another form of planet, or celestial bodies, that didn’t orbit Earth, but another planet. Before he could even determine they were moons, he had to make observations and record what he saw every night while stargazing. He first saw the mysterious objects on January 7, 1610. On that night he saw three “stars”, two on one side and the last on the other side. The following night, they were all on one side, and he noted that they weren’t stars because they had moved. Every night from then on he observed, recorded, and took notes. Those simple steps led him to the discovery of Jupiter’s four main moons; Io, Europa, Ganymede, and Callisto. Since he discovered them, he decided to name them after the ruling family of Florence, Medici, calling them the “Medicaen Planets.”

Galileo’s discovery of Jupiter’s moons was a breakthrough for Copernicus’ theory. Copernicus believed that the Earth was not at the center of the solar system, but the planets and stars actually revolve around the Sun. Jupiter’s moons helped Galileo somewhat prove that Copernicus was right and Aristotle was wrong. By Jupiter’s moons orbiting Jupiter, proved that objects could orbit another object. Galileo thought that the planets and stars might actually be orbiting the Sun.

__Planets Revolve around the Sun__
Another observation that Galileo saw was the phases of Venus and the Moon. Through his telescope Galileo saw that each night Venus had a different figure or side and he observed the same thing too with the Moon. These observations helped prove that planets revolve around the Sun. We see these phases when the side that’s being reflected by the Sun, or light, faces Earth. As it orbits the Sun, parts of Venus and the Moon that we can visibly see are the phases.

As Galileo discovered the orbits of these mysterious celestial bodies and started to believe that planets revolve around the Sun, he saw that planets don’t orbit in a perfect circle. Planets actually orbit in ellipses. An ellipse is an oval shaped pattern, that the planets revolve in around the Sun. Ellipses are when two focal points very close together, and the farther away they are from each other, the farther the object is from the other. The planets have focal points from them, but also the Sun, resulting in how far between each planet is from the Sun. Galileo realized this and drew many diagrams explaining his reasoning, making sure it made sense but also making sure he was able to prove why he’s right.

As all his reasoning and observations came into place, he finally concluded and agreed with Copernicus Theory. While the planets are rotating on their axis, they are also revolving around the Sun. Galileo proved that the Earth was not the center of the universe, it was actually the Sun. When he discovered the moons of Jupiter and the phases, he noticed that they had to be orbiting around something to change phases each night. Through his diagrams and observations he concluded that they had to orbiting a place that gave out light. The only place had to be the Sun. From then on, he agreed with Copernicus that the Earth is not the center of the solar system.

__Laws of Falling Bodies__
While Galileo was looking up into the sky and making observations, he was also excelling in physics. In one of his physics experiments, he proved Aristotle wrong, once again. Aristotle said that objects of different masses fall at different speeds and finish at different times. Galileo, knowing and excelling in physics, disagreed strongly. He wanted to convince others that Aristotle was wrong, but also, give proof just in case he had to back it up. He said the weight doesn’t matter of the objects; they will both fall at the same time and speed. To back up his hypothesis, he did an experiment from the Leaning Tower of Pisa. He took two balls of different mass, weight, and started explaining what he was doing so he could he people’s attention. There was a huge crowd as he dropped the two balls. His hypothesis was correct; he proved that balls of different masses fall at the same time. This was the second thing he did that angered the church by disagreeing with church by disagreeing with Aristotle.

Galileo’s most famous physics experiment was the pendulum. A pendulum is used for ancient clocks, for example a Grandfather clock. It sways back and forth, it’s a string with a weight, or “bob”, attached to the bottom. Galileo watched it swing and looked for patterns which soon became laws. One thing that he learned was that the weight of the bob did not change the length of the swing. Another pattern he learned was that the length of the string did change the length of swing. For the first law, Galileo experimented using different shapes, sizes, and weights of the bob. To see if the pattern recurred, he took notes during the experiment. The shape, size, or weight of the bob did not affect the length of the string. The length of the rope/string did affect the length of the swing. If the string were short, the swings would be shorter, but if the string were long the swings would be longer.

As Galileo showed that Aristotle was wrong by dropping the two cannonballs from the Leaning Tower of Pisa, he described that they fell at the same speed in characteristic pattern. He said that they had to deal with the time elapsed with its fall. His formula in words that described the law was by finding the distance covered you square the time that had passed. In Galileo’s time he used his pulse, as seconds or instants. For example if it took two instants it would travel four times as far, if it took three instants it would travel nine times as far, and if it took four instants it would travel sixteen times as far, etc. Galileo proved this by seeing lemons drop from trees and dropping cannonballs, each time he did an experiment he recorded it every time to see if a pattern kept recurring. When objects fall, the speed of their descent increases uniformity, at the same time. This means as they fall their speed basically becomes one, that’s why no matter the mass they will fall at the same speed. The speed of the objects increases from the farther it falls. All this that Galileo discovered by making observations helped us out in the future.

__Other Observations__
Another one of Galileo’s famous discoveries was Saturn’s rings. When Galileo first saw the rings through his telescope he thought they were “ears”. His telescope didn’t allow him to see that they were extensions on either side of the planet, Saturn. He also mistook Saturn’s rings as planets, thinking it was a three-bodied planet system. Later on when he observed Saturn again, the rings were oriented at Earth, making Galileo think that two of the bodies disappeared. Again in 1616 he was confused because the rings reappeared. Even though he did not actually have anything to say about the planet, he still saw them and had observations about them. He was questioned by why they disappeared and reappeared; he made little observations that helped scientists later on discover why that were so. Even though he did not actually have anything to say about the planet, he still saw them and made observations about them.

Another famous discovery that he made was the sunspots on the Sun. When Galileo first observed them he called them dark patches/spots. The sunspots are indications of reduced surface temperatures, which can be caused by rotating itself. When Galileo observed the sunspots closely with his telescope he saw that the Sun is rotating on its own axis. The discoveries of the sunspots and that the Sun is rotating on an axis, led Galileo to believe that Earth, and possibly the other planets, are rotating on its own axis. It did because when he discovered that the Sun is rotating on an axis he had reason to believe that the Earth also rotates on an axis. The sunspots helped Galileo to a breaking point that the Sun is actually at the center of the universe.

A last discovery that Galileo made was the Moon is not perfectly smooth. When he observed the Moon he noticed something really odd, it was bumpy not smooth like Aristotle and the church said it was. Every night he would draw what he saw, he saw miniature mountains, now what we call craters. In his observations he wrote that the moon is mountainous and had valleys. Another thing he observed about the Moon was that it changed phases every three or four days. Galileo proved hat Aristotle, the heavens, and the church wrong. They all believed that the Moon, and everything, was perfectly smooth which is clearly not.

Many of the observations that Galileo discovered has led to two conclusions. One being the fact that Aristotle was wrong in what he said. The other being the fact that the heavens were wrong about an unchanging imperfect heaven. Jupiter’s moons came to the conclusion that there is more than one center of motion. The mountainous Moon concludes that almost everything is not as smooth as they appear. The phases of Venus concludes that it and all the other planets, including Earth, revolves around the Sun. Galileo proved all this through his observations that he saw through his new and improved telescope. His observations helped scientists of our time come to conclusions that no one has ever thought of. Galileo is an inspiration and has definitely influenced everyone’s lives today.

__Bibliography__
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2. http://csep10.phys.utk.edu/astr161/lect/history/galileo.html

3. http://www.worldbookonline.com/advanced/article?id=ar215300&st=galileo+discoveries

4. http://www.pbs.org/wgbh/nova/galileo/science.html

5. http://www.britannica.com/EBchecked/topic/224058/Galileo

6. Panchyk, Richard. Galileo for Kids: His Life and Ideas. Chicago, IL: Chicago Review, 2005. Print.

7. Pettenati, Jeanne, and Paolo Rui. Galileo's Journal, 1609-1610. Watertown, MA: Charlesbridge, 2006. Print.

8. Galileo [videorecording] /NEST Family Entertainment and Rich Animation Studios; directed by Richard Rich; produced by Richard Rich, Jared F. Brown ; screenplay, Brian Nissen. Coppell, TX: NEST Family Entertainment, c2005